Claude-User

What user agent does Claude-User use?

Anthropic does not publish a full user agent string for Claude-User, only the name. Its Claude Code documentation says the web fetch tool sends a user agent that begins with Claude-User.

How do I block Claude-User?

Anthropic says its bots honour robots.txt, and makes no exception for fetches a person asked for. Blocking Claude-User stops Claude reading your pages to answer questions, which Anthropic says may make your site less visible in its answers.

Add this to the robots.txt file at the root of your site:

User-agent: Claude-User
Disallow: /

How do I check that a Claude-User visit is real?

Anyone can put a crawler’s name in a user agent, so the name alone proves nothing.

Anthropic publishes one list of IP addresses for all its bots, and says a crawler whose address is on it is from Anthropic.

Spreelytics runs this check for you. Every crawl that claims to be Claude-User is compared with the IP ranges Anthropic publishes, refreshed every 12 hours, and one from outside them counts as spoofed.

How do I see Claude-User visits on my site?

Your server’s access logs record the user agent of each request, so you can search them for “Claude-User”.

Or add the Spreelytics server middleware, @spreelytics/ai-crawl. It recognises Claude-User by its user agent and counts each visit on the Bots page under AI answers, as Claude, apart from your visitor numbers.

Sources: support.claude.com/en/articles/8896518-does-anthropic-crawl-data-from-the-web-and-how-can-site-owners-block-the-crawler, code.claude.com/docs/en/tools-reference